scholarly journals HDAC6 mediates an aggresome-like mechanism for NLRP3 and pyrin inflammasome activation

Science ◽  
2020 ◽  
Vol 369 (6510) ◽  
pp. eaas8995 ◽  
Author(s):  
Venkat Giri Magupalli ◽  
Roberto Negro ◽  
Yuzi Tian ◽  
Arthur V. Hauenstein ◽  
Giuseppe Di Caprio ◽  
...  
Keyword(s):  
Immune Surveillance ◽  
Inflammasome Activation ◽  
Histone Deacetylase 6 ◽  
Microtubule Organizing Center ◽  
Pyrin Domain ◽  
Microtubule Transport ◽  
Organizing Center ◽  
Aggresome Formation ◽  
Inflammatory Caspases

Inflammasomes are supramolecular complexes that play key roles in immune surveillance. This is accomplished by the activation of inflammatory caspases, which leads to the proteolytic maturation of interleukin 1β (IL-1β) and pyroptosis. Here, we show that nucleotide-binding domain, leucine-rich repeat, and pyrin domain–containing protein 3 (NLRP3)- and pyrin-mediated inflammasome assembly, caspase activation, and IL-1β conversion occur at the microtubule-organizing center (MTOC). Furthermore, the dynein adapter histone deacetylase 6 (HDAC6) is indispensable for the microtubule transport and assembly of these inflammasomes both in vitro and in mice. Because HDAC6 can transport ubiquitinated pathological aggregates to the MTOC for aggresome formation and autophagosomal degradation, its role in NLRP3 and pyrin inflammasome activation also provides an inherent mechanism for the down-regulation of these inflammasomes by autophagy. This work suggests an unexpected parallel between the formation of physiological and pathological aggregates.

In vitro nucleation of microtubules from microtubule-organizing center prepared from cellular slime mold

Cell Motility ◽  
1982 ◽  
Vol 2 (3) ◽  
pp. 257-272 ◽  
Author(s):  
Ryoko Kuriyama ◽  
Chikako Sato ◽  
Yoshio Fukui ◽  
Soryu Nishibayashi
Keyword(s):  
Slime Mold ◽  
Cellular Slime Mold ◽  
Microtubule Organizing Center ◽  
Organizing Center ◽  
Cellular Slime

scholarly journals Radial F-actin Organization During Early Neuronal Development

2018 ◽  
Author(s):  
Durga Praveen Meka ◽  
Robin Scharrenberg ◽  
Bing Zhao ◽  
Theresa König ◽  
Irina Schaefer ◽  
...  
Keyword(s):  
Neuronal Development ◽  
Super Resolution ◽  
Actin Dynamics ◽  
Cell Periphery ◽  
Microtubule Organizing Center ◽  
Actin Organization ◽  
Organizing Center ◽  
Super Resolution Microscopy ◽  
Radial Organization

AbstractThe centrosome is thought to be the major neuronal microtubule-organizing center (MTOC) in early neuronal development, producing microtubules with a radial organization. In addition, albeit in vitro, recent work showed that isolated centrosomes could serve as an actin-organizing center (Farina et al., 2016), raising the possibility that neuronal development may, in addition, require a centrosome-based actin radial organization. Here we report, using super-resolution microscopy and live-cell imaging, F-actin organization around the centrosome with dynamic F-actin aster-like structures with F-actin fibers extending and retracting actively. Photoconversion/photoactivation experiments and molecular manipulations of F-actin stability reveal a robust flux of somatic F-actin towards the cell periphery. Finally, we show that somatic F-actin intermingles with centrosomal PCM-1 satellites. Knockdown of PCM-1 and disruption of centrosomal activity not only affect F-actin dynamics near the centrosome but also in distal growth cones. Collectively the data show a radial F-actin organization during early neuronal development, which might be a cellular mechanism for providing peripheral regions with a fast and continuous source of actin polymers; hence sustaining initial neuronal development.

scholarly journals Morinda officinalis oligosaccharides alleviate depressive-like behaviors in post-stroke rats via suppressing NLRP3 inflammasome to inhibit hippocampal inflammation

2021 ◽  
Author(s):  
Zhifang Li ◽  
Hexiang Xu ◽  
Yi Xu ◽  
Guanfeng Lu ◽  
Qiwei Peng ◽  
...  
Keyword(s):  
Western Blot ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Inflammation Response ◽  
Post Stroke ◽  
Pyrin Domain ◽  
Bv2 Cells ◽  
Post Stroke Depression ◽  
Depressive Episodes

Abstract Background: Morinda officinalis oligosaccharides (MOOs) is a traditional Chinese medicine extracted from plant Morinda officinalis roots. It has been used to treat mild and moderate depressive episodes. In the present study, we investigated whether MOOs can ameliorate depressive-like behaviors in post-stroke depression (PSD) rats and further discussed its mechanism by suppressing microglial NLRP3 inflammasome activation to inhibit hippocampal inflammation.Methods: Behaviors tests were performed to evaluate the effect of MOOs on depressive-like behaviors in PSD rats. The effects of MOOs on the expression of IL-18, IL-1β and nucleotide-binding domain leucine-rich repeat family pyrin domain containing 3 (NLRP3) inflammasome were measured in both PSD rats and lipopolysaccharide (LPS)+adenosine triphosphate (ATP) stimulated BV2 cells by reverse transcription polymerase chain reaction (RT-PCR), immunofluorescence and Western blot analysis. Adeno-associated virus (AAV) were injected into hippocampus to downregulate NLRP3 inflammasome expression. The detailed molecular mechanism underlying the effects of MOOs was analyzed by Western blot and immunofluorescence.Results: MOOs can alleviate depressive-like behaviors in PSD rats. PSD rats showed increased expression of IL-18, IL-1β and NLRP3 inflammasome in the ischemic hippocampus, while MOOs compromised the elevation. NLRP3 downregulation ameliorated depressive-like behaviors and hippocampal inflammation response in PSD rats. Moreover, we found that NLRP3 is mainly expressed on microglia. In vitro, MOOs effectively inhibited the expression of IL-18, IL-1β and NLRP3 inflammasome in LPS+ ATP treated BV2 cells. We further showed that modulation of NLRP3 inflammasome by MOOs was associated with IκB/NF‐κB p65 signaling pathway.Conclusion: Overall, our study revealed the antidepressive effect of MOOs on PSD rats through modulation of microglial NLRP3 inflammasome. We also provide a novel insight into hippocampal inflammation response in PSD pathology and put forward NLRP3 inflammasome as a potential therapeutic target for PSD.

Autoinflammatory disease with corneal and mucosal dyskeratosis caused by a novel NLRP1 variant

Rheumatology ◽  
2019 ◽  
Vol 59 (9) ◽  
pp. 2334-2339 ◽  
Author(s):  
Troels Herlin ◽  
Sofie E Jørgensen ◽  
Christian Høst ◽  
Patrick S Mitchell ◽  
Maria Hønholt Christensen ◽  
...  
Keyword(s):  
Sanger Sequencing ◽  
Mononuclear Cells ◽  
Novel Mutation ◽  
Mucosal Inflammation ◽  
Inflammasome Activation ◽  
Incomplete Penetrance ◽  
Peripheral Blood Mononuclear ◽  
Pyrin Domain ◽  
Patient Pbmcs

Abstract Objectives Here we investigated a patient with inflammatory corneal intraepithelial dyskeratosis, mucosal inflammation, tooth abnormalities and, eczema to uncover the genetic and immunological basis of the disease. Methods On suspicion of an autoinflammatory condition, Sanger sequencing of nucleotide-binding oligomerization domain-like, leucine-rich repeat pyrin domain containing 1 (NLRP1) was performed and combined with an in vitro inflammasome reconstitution assay to measure caspase-1-mediated IL-1β cleavage, stimulation of patient peripheral blood mononuclear cells (PBMCs) and whole blood to measure IL-1β, IL-18 production and quantification of apoptosis-associated speck-like protein containing CARD (ASC) speck formation as a measure of inflammasome activation by flow cytometry. Results Sanger sequencing revealed a novel mutation (c.175G>C, p.A59P; NM_33004.4) in the inflammasome molecule NLRP1 segregating with disease, although with incomplete penetrance, in three generations. We found that patient PBMCs produced increased IL-1β in response to inflammatory stimuli, as well as increased constitutive levels of IL-18. Moreover, we demonstrate that expression of the identified NLRP1 A59P variant caused spontaneous IL-1β cleavage to mature IL-1β. In addition, patient PBMCs responded to NLRP1 stimulation with increased ASC speck formation as a reflection of elevated inflammasome activity. Conclusion We demonstrate that this novel NLRP1 A59P variant caused increased activation of the NLRP1 inflammasome, resulting in constitutively and inducibly elevated IL-1β and IL-18 synthesis. We suggest the NLRP1 mutation underlies the pathogenesis of this rare autoinflammatory dyskeratotic disease inherited in an autosomal dominant manner with incomplete penetrance in the patient and within the family for several generations.

A protein related to brain microtubule-associated protein MAP1B is a component of the mammalian centrosome

1994 ◽  
Vol 107 (2) ◽  
pp. 601-611 ◽  
Author(s):  
J.E. Dominguez ◽  
B. Buendia ◽  
C. Lopez-Otin ◽  
C. Antony ◽  
E. Karsenti ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Cultured Cells ◽  
Polyclonal Antibodies ◽  
Microtubule Organizing Center ◽  
Microtubule Associated Proteins ◽  
Organizing Center ◽  
Associated Proteins ◽  
Pericentriolar Material ◽  
Peptide Maps

The centrosome is the main microtubule organizing center of mammalian cells. Structurally, it is composed of a pair of centrioles surrounded by a fibro-granular material (the pericentriolar material) from which microtubules are nucleated. However, the nature of centrosomal molecules involved in microtubules nucleation is still obscure. Since brain microtubule-associated proteins (MAPs) lower the critical tubulin concentration required for microtubule nucleation in tubulin solution in vitro, we have examined their possible association with centrosomes. By immunofluorescence, monoclonal and polyclonal antibodies raised against MAP1B stain the centrosome in cultured cells as well as purified centrosomes, whereas antibodies raised against MAP2 give a completely negative reaction. The MAP1B-related antigen is localized to the pericentriolar material as revealed by immunoelectron microscopy. In preparations of purified centrosomes analyzed on poly-acrylamide gels, a protein that migrates as brain MAP1B is present. After blotting on nitrocellulose, it is decorated by anti-MAP1B antibodies and the amino acid sequence of proteolytic fragments of this protein is similar to brain MAP1B. Moreover, brain MAP1B and its centrosomal counterpart share the same phosphorylation features and have similar peptide maps. These data strongly suggest that a protein homologue to MAP1B is present in centrosomes and it is a good candidate for being involved in the nucleating activity of the pericentriolar material.

A novel structural component of the Dictyostelium centrosome

1996 ◽  
Vol 109 (13) ◽  
pp. 3103-3112 ◽  
Author(s):  
A. Kalt ◽  
M. Schliwa
Keyword(s):  
Mitotic Spindle ◽  
Structural Component ◽  
Myosin Ii ◽  
Live Cells ◽  
Microtubule Organizing Center ◽  
Direct Role ◽  
Cytoplasmic Microtubule ◽  
Interphase Cells ◽  
Organizing Center

The microtubule-organizing center of D. discoideum is a nucleus-associated body (NAB) that consists of a multilayered, box-shaped core embedded in an amorphous corona from which the microtubules emerge. The composition of the NAB is still largely unresolved. Here we have examined a high molecular mass component of the NAB which was identified by a monoclonal antibody raised against isolated nucleus/NAB complexes. This antibody recognized a 350 kDa component which is immunologically related to the D. discoideum heavy chain of myosin II. The 350 kDa antigen was localized only at the NAB in interphase cells, while in mitotic cells it may also be found in the vicinity of the NAB as well as in association with the mitotic spindle. Immunogold labeling experiments showed that the protein is part of the NAB corona. This association was not destroyed by treatment with 2 M urea or 0.6 M KCl. The 350 kDa antigen was part of the thiabendazole-induced cytoplasmic microtubule-organizing centers. A direct role in the polymerization of tubulin could not be determined in an in vitro microtubule nucleation assay, whereas antibody electroporation of live cells appeared to interfere with the generation of a normal microtubule system in a subset of cells. Our observations suggest that the 350 kDa antigen is a structural component of the NAB corona which could be involved in its stabilization.

scholarly journals Distribution of microtubule organizing centers in migrating sheets of endothelial cells.

1981 ◽  
Vol 91 (2) ◽  
pp. 589-594 ◽  
Author(s):  
A I Gotlieb ◽  
L M May ◽  
L Subrahmanyan ◽  
V I Kalnins
Keyword(s):  
Endothelial Cells ◽  
Monolayer Culture ◽  
Cell Movement ◽  
Time Lapse ◽  
Microtubule Organizing Center ◽  
Organizing Center ◽  
Direction Of Movement ◽  
The Relationship ◽  
Wounded Area

This study was designed to investigate the relationship between the position of the microtubule organizing center (MTOC) and the direction of migration of a sheet of endothelial cells (EC). Using immunofluorescence and phase microscopy the MTOC's of migrating EC were visualized as the cells moved into an in vitro experimental wound produced by mechanical denudation of part of a confluent monolayer culture. Although the MTOC's in nonmigrating EC were randomly positioned in relation to the nucleus, in migrating cells the position of the MTOC's changed so that 80% of the cells had the MTOC positioned in front of the nucleus toward the direction of movement of the endothelial sheet. This repositioning of the MTOC occurred within the first 4 h after wounding and was associated with the beginning of migration of EC's into the wounded area as seen by time-lapse cinemicrophotography. These studies focus attention on the MTOC as a cytoskeletal structure that may play a role in determining the direction of cell movement.

scholarly journals Adenovirus Exploits the Cellular Aggresome Response To Accelerate Inactivation of the MRN Complex

2005 ◽  
Vol 79 (22) ◽  
pp. 14004-14016 ◽  
Author(s):  
Yue Liu ◽  
Anna Shevchenko ◽  
Andrej Shevchenko ◽  
Arnold J. Berk
Keyword(s):  
Inclusion Bodies ◽  
Cytoplasmic Inclusion ◽  
Retrograde Transport ◽  
Cellular Protein ◽  
Nuclear Bodies ◽  
Degenerative Diseases ◽  
Microtubule Organizing Center ◽  
Viral Dna ◽  
Organizing Center ◽  
Aggresome Formation

ABSTRACT Results reported here indicate that adenovirus 5 exploits the cellular aggresome response to accelerate inactivation of MRE11-RAD50-NBS1 (MRN) complexes that otherwise inhibit viral DNA replication and packaging. Aggresomes are cytoplasmic inclusion bodies, observed in many degenerative diseases, that are formed from aggregated proteins by dynein-dependent retrograde transport on microtubules to the microtubule organizing center. Viral E1B-55K protein forms aggresomes that sequester p53 and MRN in transformed cells and in cells transfected with an E1B-55K expression vector. During adenovirus infection, the viral protein E4orf3 associates with MRN in promyelocytic leukemia protein nuclear bodies before MRN is bound by E1B-55K. Either E4orf3 or E4orf6 is required in addition to E1B-55K for E1B-55K aggresome formation and MRE11 export to aggresomes in adenovirus-infected cells. Aggresome formation contributes to the protection of viral DNA from MRN activity by sequestering MRN in the cytoplasm and greatly accelerating its degradation by proteosomes following its ubiquitination by the E1B-55K/E4orf6/elongin BC/Cullin5/Rbx1 ubiquitin ligase. Our results show that aggresomes significantly accelerate protein degradation by the ubiquitin-proteosome system. The observation that a normal cellular protein is inactivated when sequestered into an aggresome through association with an aggresome-inducing protein has implications for the potential cytotoxicity of aggresome-like inclusion bodies in degenerative diseases.

scholarly journals The Roles of Inflammasomes in Host Defense against Mycobacterium tuberculosis

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 120
Author(s):  
Jialu Ma ◽  
Shasha Zhao ◽  
Xiao Gao ◽  
Rui Wang ◽  
Juan Liu ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Host Defense ◽  
Inflammatory Responses ◽  
Inflammasome Activation ◽  
Caspase Activation ◽  
Nucleotide Binding Domain ◽  
Caspase 1 ◽  
Pyrin Domain

Mycobacterium tuberculosis (MTB) infection is characterized by granulomatous lung lesions and systemic inflammatory responses during active disease. Inflammasome activation is involved in regulation of inflammation. Inflammasomes are multiprotein complexes serving a platform for activation of caspase-1, which cleaves the proinflammatory cytokines such as interleukin-1β (IL-1β) and IL-18 into their active forms. These cytokines play an essential role in MTB control. MTB infection triggers activation of the nucleotide-binding domain, leucine-rich-repeat containing family, pyrin domain-containing 3 (NLRP3) and absent in melanoma 2 (AIM2) inflammasomes in vitro, but only AIM2 and apoptosis-associated speck-like protein containing a caspase-activation recruitment domain (ASC), rather than NLRP3 or caspase-1, favor host survival and restriction of mycobacterial replication in vivo. Interferons (IFNs) inhibits MTB-induced inflammasome activation and IL-1 signaling. In this review, we focus on activation and regulation of the NLRP3 and AIM2 inflammasomes after exposure to MTB, as well as the effect of inflammasome activation on host defense against the infection.

scholarly journals Inflammasome activation in neutrophils of patients with severe COVID-19

2022 ◽  
Author(s):  
Karen Aymonnier ◽  
Julie Ng ◽  
Laura E Fredenburgh ◽  
Katherin Zambrano-Vera ◽  
Patrick Münzer ◽  
...  
Keyword(s):  
Time Lapse ◽  
Sterile Inflammation ◽  
Inflammasome Activation ◽  
Microtubule Organizing Center ◽  
Reporter Mice ◽  
Organizing Center ◽  
Monocytes And Macrophages ◽  
Histone Citrullination ◽  
Net Release

Infection by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) engages the inflammasome in monocytes and macrophages and leads to the cytokine storm in COVID-19. Neutrophils, the most abundant leukocytes, release neutrophil extracellular traps (NETs), which have been implicated in the pathogenesis of COVID-19. Our recent study shows that activation of the NLRP3 inflammasome is important for NET release in sterile inflammation. However, the role of neutrophil inflammasome formation in human disease is unknown. We hypothesized that SARS-COV-2 infection may induce inflammasome activation in neutrophils. We also aimed to assess the localization of inflammasome formation, (i.e. ASC speck assembly), and timing relative to NETosis in stimulated neutrophils by real time video microscopy. Neutrophils isolated from severe COVID-19 patients demonstrated that approximately 2% of neutrophils in both the peripheral blood and tracheal aspirates presented ASC speck. ASC speck was observed in neutrophils with an intact poly-lobulated nucleus, suggesting early formation during neutrophil activation. Additionally, 40% of nuclei were positive for citrullinated histone H3, and there was a significant correlation between speck formation and nuclear histone citrullination. Time-lapse microscopy in LPS-stimulated neutrophils from fluorescent ASC reporter mice showed that ASC speck formed transiently and at the microtubule organizing center, long before NET release. Our study shows that ASC speck is present in neutrophils from COVID-19 patients with respiratory failure and that it forms early in NETosis. Our findings suggest that inhibition of neutrophil inflammasomes may be beneficial in COVID-19.

Sign in / Sign up

Export Citation Format

Share Document